Prof Bruce Yardley

Professor of Metamorphic Geochemistry

Biography

Research

My research interests are in fluid processes in the Earth's crust, and span a wide range of topics, including aspects of ore formation, diagenesis and prograde and retrograde metamorphism, taking place at all levels in the crust. I am particularly interested in chemical mass transfer by fluids and in the cycle of interactions between fluid flow, temperature, mineralogical reactions and the rheology and permeability of the crust. The techniques that my group has employed in recent years include field and petrographic observations, rock and mineral analysis, fluid inclusion studies (including multi-element chemical analysis), experimental studies and geochemical modelling of fluid rock interaction. I am interested both in exploiting results from the study of active processes today for the improved understanding of ancient flow regimes, and in understanding how human activity in the subsurface may modify natural processes in the future.

My major research activity at the present time is in 3 areas.

1) Crustal fluid compositions and the formation of hydrothermal ores. I have been investigating the metal contents of crustal fluids for a number of years, including establishing an LA-ICP-MS laboratory for fluid inclusion analysis in collaboration with David Banks. We installed an Agilent 7500c ICP-MS and a Geolas Q excimer laser system which was optimised for laser ablation analysis of fluid inclusions in natural and synthetic quartz. The development of the methods is described in Allan et al. (2005) while the fluid inclusions LAICPMS software that Murray Allan originally developed in Leeds, known as SILLS, is described in Guillong et al. (2008). My work on crustal fluid compositions and metal transport has resulted in a several review papers featuring different aspects of metal transport and fluid processes (Yardley 2005, 2009, 2012, Yardley & Cleverley 2013). Current work on hydrothermal ores is being carried out as part of the NEETE and GEMCREE projects of the NERC SoS Minerals Programme.

2) Fluid-rock interactions arising from the injection of CO2 into water-bearing sedimentary formations. I was part of the NERC UK Carbon Capture and Storage Consortium, and this has led to further work through the NERC CRIUS Consortium, with Cambridge, Manchester and BGS and the EPSRC CO2FLIP project with Sheffield, Aberdeen and Tsinghua University, Beijing. Work with Andrew Kilpatrick and Joergen Rosenqvist (CRIUS) has concentrated on experimental studies of the rates of mineral dissolution triggered by CO2 injection (Rosenqvist et al. 2012, Kaszuba et al. 2013), while work with Benoit Lamy-Chappuis (CO2FLIP) has involved directly measuring and modelling the impact of calcite dissolution on rock permeability (Lamy-Chappuis et al. 2014)

3) Water residence in the deep crust and the influence of mineral-fluid interactions on the strength of the crust. I have been collaborating with Prof Wilhelm Heinrich's group at GFZ Potsdam to investigate the kinetics of hydration reactions, most recently with support from a Humboldt Research Award of the Alexander von Humboldt Foundation (2009-11). This work involved hydrothermal experiments at 300 – 500oC and has demonstrated that old metamorphic rocks residing in cooled crust react with free water on a scale of hundreds of years, so that the frequent survival of ancient high grade rocks demonstrates that deep stable crystalline crust remains dry over geological time, except locally in fractures (Yardley et al. 2010, Yardley et al. 2014).

I have recently been seconded to the RWMD to take on a 60% role as Chief Geologist. I have a long-standing interest in the problems of disposal of nuclear waste, which my research interests are closely allied to. I was Science Secretary of the Geological Society of London in 2005 and took the lead in organising a one-day meeting on “Geosciences and the Long Term Management of Radioactive Wastes” which brought together international experts in geological disposal together with members of CoRWM, the committee tasked with drawing up recommendations as to how the UK government should deal with Radioactive Waste. Subsequently I helped organise a 2008 meeting “The Geological Disposal of Radioactive waste: How geologists understand the Earth beneath our feet”, intended to explain to non-specialists what geologists and geophysicists could and could not be expected to deduce about a possible site prior to excavation. In January 2013, I was asked to meet with the Cumbria group of MPs as an independent geologist at a fact-finding session on a possible Geological Disposal Facility in their region.

Like many Earth scientists, I am concerned that we find a permanent repository for the UK’s inventory of radioactive waste. The process of securing local agreement has taken time in every country, but other European countries have gained the confidence and support of local communities and are more advanced in the process than this country. Learning from the experience of our neighbours, we in the UK now have the opportunity to look afresh for a suitable site from first principles, and I am delighted to have had the opportunity to join the team which will establish a suitable site for our radioactive waste and thereby help safeguard the future for countless generations to come.